Movement Detection of a Head Mounted Device

8. The head mounted device of claim 1, wherein the at least one light emitter comprises a light emitting diode configured to output red light or near infrared light.

12. The system of claim 10, wherein the one or more light guides include at least one light guide that includes a beveled end.

18. The method of claim 17, wherein the one or more pixels depict at least one of dermal features of the nose or subdermal features of the nose.

20. The method of claim 16, wherein the first image and the second image are obtained by the image sensor based at least in part on an illumination of at least the portion of the nose of the user by a light emitter.

27. The head mounted device of claim 1, wherein the at least one light emitter is positioned at the nose-facing side of the bridge portion.

30. The head mounted device of claim 1, wherein the first eye portion and the second eye portion extend below a bottom of the at least one image sensor and a bottom of the one or more light guides.